From d9d94ac86ba0193c897d1fc80b551996ae959d50 Mon Sep 17 00:00:00 2001 From: Alan Modra Date: Fri, 24 Jan 2014 23:17:28 +1030 Subject: [PATCH] TLS orphan section placement Ensures TLS orphans are placed adjacent to existing TLS sections, and fixes places where the output_section_statement flags (which might not be set) were tested when bfd_section flags were available. * ldlang.c (lang_output_section_find_by_flags): Be careful to test look->bfd_section->flags if available rather than look->flags. Separate SEC_THREAD_LOCAL handling from SEC_READONLY loop, and rewrite. --- ld/ChangeLog | 7 ++++ ld/ldlang.c | 134 ++++++++++++++++++++++++++++++++++++----------------------- 2 files changed, 89 insertions(+), 52 deletions(-) diff --git a/ld/ChangeLog b/ld/ChangeLog index 59e9d36..9beee8c 100644 --- a/ld/ChangeLog +++ b/ld/ChangeLog @@ -1,3 +1,10 @@ +2014-01-24 Alan Modra + + * ldlang.c (lang_output_section_find_by_flags): Be careful to + test look->bfd_section->flags if available rather than + look->flags. Separate SEC_THREAD_LOCAL handling from + SEC_READONLY loop, and rewrite. + 2014-01-22 Alan Modra * ldlang.c (asneeded_list_head, asneeded_list_tail): New vars. diff --git a/ld/ldlang.c b/ld/ldlang.c index 1a0d48f..9903f70 100644 --- a/ld/ldlang.c +++ b/ld/ldlang.c @@ -1495,7 +1495,7 @@ lang_output_section_find_by_flags (const asection *sec, lang_match_sec_type_func match_type) { lang_output_section_statement_type *first, *look, *found; - flagword flags; + flagword look_flags, sec_flags, differ; /* We know the first statement on this list is *ABS*. May as well skip it. */ @@ -1503,21 +1503,22 @@ lang_output_section_find_by_flags (const asection *sec, first = first->next; /* First try for an exact match. */ + sec_flags = sec->flags; found = NULL; for (look = first; look; look = look->next) { - flags = look->flags; + look_flags = look->flags; if (look->bfd_section != NULL) { - flags = look->bfd_section->flags; + look_flags = look->bfd_section->flags; if (match_type && !match_type (link_info.output_bfd, look->bfd_section, sec->owner, sec)) continue; } - flags ^= sec->flags; - if (!(flags & (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_READONLY - | SEC_CODE | SEC_SMALL_DATA | SEC_THREAD_LOCAL))) + differ = look_flags ^ sec_flags; + if (!(differ & (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_READONLY + | SEC_CODE | SEC_SMALL_DATA | SEC_THREAD_LOCAL))) found = look; } if (found != NULL) @@ -1527,115 +1528,144 @@ lang_output_section_find_by_flags (const asection *sec, return found; } - if ((sec->flags & SEC_CODE) != 0 - && (sec->flags & SEC_ALLOC) != 0) + if ((sec_flags & SEC_CODE) != 0 + && (sec_flags & SEC_ALLOC) != 0) { /* Try for a rw code section. */ for (look = first; look; look = look->next) { - flags = look->flags; + look_flags = look->flags; if (look->bfd_section != NULL) { - flags = look->bfd_section->flags; + look_flags = look->bfd_section->flags; if (match_type && !match_type (link_info.output_bfd, look->bfd_section, sec->owner, sec)) continue; } - flags ^= sec->flags; - if (!(flags & (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD - | SEC_CODE | SEC_SMALL_DATA | SEC_THREAD_LOCAL))) + differ = look_flags ^ sec_flags; + if (!(differ & (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD + | SEC_CODE | SEC_SMALL_DATA | SEC_THREAD_LOCAL))) found = look; } } - else if ((sec->flags & (SEC_READONLY | SEC_THREAD_LOCAL)) != 0 - && (sec->flags & SEC_ALLOC) != 0) + else if ((sec_flags & SEC_READONLY) != 0 + && (sec_flags & SEC_ALLOC) != 0) { /* .rodata can go after .text, .sdata2 after .rodata. */ for (look = first; look; look = look->next) { - flags = look->flags; + look_flags = look->flags; if (look->bfd_section != NULL) { - flags = look->bfd_section->flags; + look_flags = look->bfd_section->flags; if (match_type && !match_type (link_info.output_bfd, look->bfd_section, sec->owner, sec)) continue; } - flags ^= sec->flags; - if (!(flags & (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD - | SEC_READONLY | SEC_SMALL_DATA)) - || (!(flags & (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD - | SEC_READONLY)) - && !(look->flags & SEC_SMALL_DATA)) - || (!(flags & (SEC_THREAD_LOCAL | SEC_ALLOC)) - && (look->flags & SEC_THREAD_LOCAL) - && (!(flags & SEC_LOAD) - || (look->flags & SEC_LOAD)))) + differ = look_flags ^ sec_flags; + if (!(differ & (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD + | SEC_READONLY | SEC_SMALL_DATA)) + || (!(differ & (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD + | SEC_READONLY)) + && !(look_flags & SEC_SMALL_DATA))) found = look; } } - else if ((sec->flags & SEC_SMALL_DATA) != 0 - && (sec->flags & SEC_ALLOC) != 0) + else if ((sec_flags & SEC_THREAD_LOCAL) != 0 + && (sec_flags & SEC_ALLOC) != 0) + { + /* .tdata can go after .data, .tbss after .tdata. Treat .tbss + as if it were a loaded section, and don't use match_type. */ + bfd_boolean seen_thread_local = FALSE; + + match_type = NULL; + for (look = first; look; look = look->next) + { + look_flags = look->flags; + if (look->bfd_section != NULL) + look_flags = look->bfd_section->flags; + + differ = look_flags ^ (sec_flags | SEC_LOAD | SEC_HAS_CONTENTS); + if (!(differ & (SEC_THREAD_LOCAL | SEC_ALLOC))) + { + /* .tdata and .tbss must be adjacent and in that order. */ + if (!(look_flags & SEC_LOAD) + && (sec_flags & SEC_LOAD)) + /* ..so if we're at a .tbss section and we're placing + a .tdata section stop looking and return the + previous section. */ + break; + found = look; + seen_thread_local = TRUE; + } + else if (seen_thread_local) + break; + else if (!(differ & (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD))) + found = look; + } + } + else if ((sec_flags & SEC_SMALL_DATA) != 0 + && (sec_flags & SEC_ALLOC) != 0) { /* .sdata goes after .data, .sbss after .sdata. */ for (look = first; look; look = look->next) { - flags = look->flags; + look_flags = look->flags; if (look->bfd_section != NULL) { - flags = look->bfd_section->flags; + look_flags = look->bfd_section->flags; if (match_type && !match_type (link_info.output_bfd, look->bfd_section, sec->owner, sec)) continue; } - flags ^= sec->flags; - if (!(flags & (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD - | SEC_THREAD_LOCAL)) - || ((look->flags & SEC_SMALL_DATA) - && !(sec->flags & SEC_HAS_CONTENTS))) + differ = look_flags ^ sec_flags; + if (!(differ & (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD + | SEC_THREAD_LOCAL)) + || ((look_flags & SEC_SMALL_DATA) + && !(sec_flags & SEC_HAS_CONTENTS))) found = look; } } - else if ((sec->flags & SEC_HAS_CONTENTS) != 0 - && (sec->flags & SEC_ALLOC) != 0) + else if ((sec_flags & SEC_HAS_CONTENTS) != 0 + && (sec_flags & SEC_ALLOC) != 0) { /* .data goes after .rodata. */ for (look = first; look; look = look->next) { - flags = look->flags; + look_flags = look->flags; if (look->bfd_section != NULL) { - flags = look->bfd_section->flags; + look_flags = look->bfd_section->flags; if (match_type && !match_type (link_info.output_bfd, look->bfd_section, sec->owner, sec)) continue; } - flags ^= sec->flags; - if (!(flags & (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD - | SEC_SMALL_DATA | SEC_THREAD_LOCAL))) + differ = look_flags ^ sec_flags; + if (!(differ & (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD + | SEC_SMALL_DATA | SEC_THREAD_LOCAL))) found = look; } } - else if ((sec->flags & SEC_ALLOC) != 0) + else if ((sec_flags & SEC_ALLOC) != 0) { /* .bss goes after any other alloc section. */ for (look = first; look; look = look->next) { - flags = look->flags; + look_flags = look->flags; if (look->bfd_section != NULL) { - flags = look->bfd_section->flags; + look_flags = look->bfd_section->flags; if (match_type && !match_type (link_info.output_bfd, look->bfd_section, sec->owner, sec)) continue; } - flags ^= sec->flags; - if (!(flags & SEC_ALLOC)) + differ = look_flags ^ sec_flags; + if (!(differ & SEC_ALLOC)) found = look; } } @@ -1644,11 +1674,11 @@ lang_output_section_find_by_flags (const asection *sec, /* non-alloc go last. */ for (look = first; look; look = look->next) { - flags = look->flags; + look_flags = look->flags; if (look->bfd_section != NULL) - flags = look->bfd_section->flags; - flags ^= sec->flags; - if (!(flags & SEC_DEBUGGING)) + look_flags = look->bfd_section->flags; + differ = look_flags ^ sec_flags; + if (!(differ & SEC_DEBUGGING)) found = look; } return found; -- 2.7.4